Drush is a very powerful tool in any Drupal site-builder's toolbox. While Drush has lots of great features and commands, sometimes it just doesn't have one you would really like to be available. Well, Drush is designed like Drupal, and it is very extensible. We have a new series out, called Coding for Drush, which teaches you how to create your own, custom Drush commands for the tedious tasks you'd like to make quicker. We have a free video that kicks off the series by explaining what a Drush command is, and how Drush knows where to find them.
If you'd like to get a sense of all the cool things we'll be covering in the series, Joe gives an overview in this introduction video: